20
TROUBLESHOOTING
b4
E_b4
Bl
ow
er
M
ot
or
-
Cur
rent
T
rip (
or
) Los
t R
ot
or
•
Fan
/m
ot
or
obs
truc
tion or
abnor
m
al
m
ot
or
loadi
ng
•
Pow
er
int
er
rupt
ion
(low
vol
tage
)
•
Hi
gh l
oadi
ng c
ondi
tions
, bl
oc
ked f
ilt
er
s
•
Bl
oc
kage i
n t
he ai
rfl
ow
(duc
tw
or
k)
or
duc
tw
or
k under
si
zed
•
Chec
k f
or
obs
truc
tion on t
he f
an
/m
ot
or
/duc
tw
or
k
•
Ver
ify
the i
nput
vol
tage at
the m
ot
or
•
Chec
k f
ilt
er
s,
gr
ills
, d
uc
t s
ys
te
m
, c
oil a
ir in
le
t/out
let
for
bl
oc
kages
.
•
Repl
ac
e m
ot
or
b6
E_b6
•
Bl
ow
er
m
ot
or
s
tops
for
ov
er
/under
vol
tage
•
Bow
er
m
ot
or
s
tops
due t
o P
CB
ov
er
heat
ing
•
Hi
gh A
C l
ine v
ol
tage t
o I
D bl
ow
er
•
Low
A
C l
ine v
ol
tage t
o I
D bl
ow
er
•
Hi
gh am
bi
ent
tem
per
at
ur
es
•
Inc
or
rec
t w
iri
ng
•
Fan
/m
ot
or
obs
truc
tion or
bl
oc
kage i
n t
he ai
rfl
ow
•
Ver
ify
li
ne v
ol
tage t
o bl
ow
er
is
w
ithi
n t
he r
ange s
pec
ified on t
he I
D bl
ow
er
rat
ing pl
at
e
•
See
"Ins
tal
lat
ion I
ns
truc
tions
" f
or
ins
tal
lat
ion r
equi
rem
ent
s
•
Chec
k pow
er
to ai
r handl
er
bl
ow
er
•
Chec
k f
or
obs
truc
tion on t
he f
an
/m
ot
or
/duc
tw
or
k
•
Chec
k w
iri
ng
•
Repl
ac
e m
ot
or
b7
E_b7
ID
bl
ow
er
m
ot
or
does
not
hav
e
requi
red par
am
et
er
s t
o f
unc
tion.
•
W
rong
/ no s
har
ed dat
a on t
he net
wor
k
•
Loc
ked m
ot
or
rot
or
c
ondi
tion
•
Chec
k f
or
loc
ked r
ot
or
c
ondi
tion
(s
ee abov
e er
ror
c
ode f
or
det
ai
ls
)
•
Repl
ac
e c
irc
ui
t boar
d or
m
ot
or
b9
E_b9
Low
Indoor
A
irf
low
(w
ithout
E
lec
tri
c H
eat
m
ode)
•
Fan
/m
ot
or
obs
truc
tion or
bl
oc
ked f
ilt
er
s
•
Res
tri
ct
ive duc
tw
or
k or
duc
tw
or
k under
si
zed
•
W
iri
ng di
sc
onnec
ted
•
W
rong out
door
/indoor
c
om
bi
nat
ion
•
ID
m
ot
or
fai
lur
e
•
Chec
k f
or
obs
truc
tion on t
he f
an
/m
ot
or
•
Chec
k duc
tw
or
k/
filt
er
for
bl
oc
kage
, c
lean f
ilt
er
s
•
Rem
ov
e obs
truc
tion
. V
er
ify
al
l r
egi
st
er
s ar
e f
ul
ly
open
•
Chec
k t
he c
onnec
tions
and t
he r
ot
at
ion of
the m
ot
or
•
Ver
ify
the i
nput
vol
tage at
the m
ot
or
•
Ver
ify
duc
tw
or
k i
s appr
opr
iat
el
y s
iz
ed f
or
s
ys
tem
. R
es
iz
e/
repl
ac
e duc
tw
or
k i
f needed
•
Repl
ac
e m
ot
or
9b
E_9b
Low
Indoor
A
irf
low
(w
ith E
lec
tri
c H
eat
m
ode)
•
Fan
/m
ot
or
obs
truc
tion or
bl
oc
ked f
ilt
er
s
•
Res
tri
ct
ive duc
tw
or
k or
duc
tw
or
k under
si
zed
•
ID
m
ot
or
fai
lur
e
•
W
iri
ng di
sc
onnec
ted
•
Chec
k f
or
obs
truc
tion on t
he f
an
/m
ot
or
•
Chec
k duc
tw
or
k/
filt
er
for
bl
oc
kage
, c
lean f
ilt
er
s
•
Rem
ov
e obs
truc
tion
. V
er
ify
al
l r
egi
st
er
s ar
e f
ul
ly
open
•
Chec
k t
he c
onnec
tions
and t
he r
ot
at
ion of
the m
ot
or
•
Ver
ify
the i
nput
vol
tage at
the m
ot
or
•
Ver
ify
duc
tw
or
k i
s appr
opr
iat
el
y s
iz
ed f
or
s
ys
tem
. R
es
iz
e/
repl
ac
e duc
tw
or
k i
f needed
•
Repl
ac
e m
ot
or
70
E_70
EE
V di
sc
onnec
tion det
ec
ted
•
Indoor
E
EV
c
oi
l not
c
onnec
ted
•
Inc
or
rec
t w
iri
ng t
o E
EV
•
Chec
k I
ndoor
E
EV
c
oi
l c
onnec
tion
(P
CB
and j
unc
tion c
onnec
tor
)
•
Repl
ac
e E
EV
c
oi
l
•
Chec
k t
he r
es
is
tanc
e v
al
ue of
E
EV
c
oi
l (
ref
er
s
er
vic
e m
anual
)
•
Repl
ac
e t
he c
ont
rol
boar
d
73
E_73
Li
qui
d s
ide t
her
m
is
tor
abnor
m
al
ity
•
O
pen
(or
) s
hor
t c
irc
ui
t of
the l
iqui
d t
her
m
is
tor
(X
5A
)
•
Li
qui
d t
her
m
is
tor
readi
ng i
nc
or
rec
t or
val
ues
out
si
de t
he nor
m
al
range
•
Chec
k t
he c
onnec
tion t
o l
iqui
d t
her
m
is
tor
(P
CB
and j
unc
tion c
onnec
tor
)
•
Chec
k t
he r
es
is
tanc
e v
al
ue of
the t
her
m
is
tor
(r
ef
er
s
er
vic
e m
anual
)
•
Repl
ac
e t
her
m
is
tor
•
Repl
ac
e t
he c
ont
rol
boar
d
74
E_74
G
as
s
ide t
her
m
is
tor
abnor
m
al
ity
•
O
pen
(or
) s
hor
t c
irc
ui
t of
the gas
ther
m
is
tor
(X
5A
)
•
G
as
ther
m
is
tor
readi
ng i
nc
or
rec
t or
val
ues
out
si
de t
he nor
m
al
range
•
Chec
k t
he c
onnec
tion t
o gas
ther
m
is
tor
(P
CB
and j
unc
tion c
onnec
tor
)
•
Chec
k t
he r
es
is
tanc
e v
al
ue of
the t
her
m
is
tor
(r
ef
er
s
er
vic
e m
anual
)
•
Repl
ac
e t
her
m
is
tor
•
Repl
ac
e t
he c
ont
rol
boar
d
75
E_75
Pr
es
sur
e s
ens
or
abnor
m
al
ity
•
O
pen
(or
) s
hor
t c
irc
ui
t of
the P
res
sur
e s
ens
or
(X
15
A)
•
Pr
es
sur
e s
ens
or
readi
ng i
nc
or
rec
t or
val
ues
out
si
de t
he nor
m
al
range
•
Chec
k t
he c
onnec
tion t
o pr
es
sur
e s
ens
or
(P
CB
and j
unc
tion c
onnec
tor
)
•
Chec
k t
he out
put
vol
tage of
the pr
es
sur
e s
ens
or
(r
ef
er
s
er
vic
e m
anual
)
•
Repl
ac
e pr
es
sur
e s
ens
or
•
Repl
ac
e t
he c
ont
rol
boar
d
77
E_77
Indoor
U
ni
t -
T
her
m
os
tat
com
m
uni
cat
ion er
ror
(s
tar
t-up &
dur
ing oper
at
ion)
•
Inc
or
rec
t w
iri
ng bet
ween I
D uni
t and t
her
m
os
tat
.
The s
ys
tem
m
ay
hav
e t
he c
om
m
uni
cat
ion er
ror
w
ithout
er
ror
c
ode 77
on t
he i
ndoor
P
CB
. F
ol
low
s
ec
tion 17.
5 S
YS
TE
M
T
RO
UB
LE
SH
O
O
TI
NG
•
Ther
m
os
tat
fai
lur
e
•
Pow
er
int
er
rupt
ion
(low
vol
tage
)
•
Chec
k f
or
ther
m
os
tat
and i
ndoor
uni
t w
iri
ng
•
Ver
ify
the i
nput
vol
tage at
the I
D uni
t and t
her
m
os
tat
Af
ter
rec
ov
er
ing t
he s
ys
tem
w
ith pow
er
s
uppl
y,
T
ST
AT
ID
N
O
C
O
M
w
ill c
ont
inue t
o b
e
di
spl
ay
ed on t
he t
her
m
os
tat
w
ithi
n 2 m
inut
es
. T
he er
ror
c
ode w
ill b
e c
lear
ed aut
om
at
ic
al
ly.
•
Repl
ac
e c
ont
rol
boar
d or
ther
m
os
tat
•
Pr
es
s
"L
EAR
N"
but
ton on P
CB
for
m
or
e t
han
5
sec
onds
to r
ees
tabl
is
h net
wor
k
Co
rr
ect
ive
A
ct
io
ns
Erro
r
Co
de
PCB L
ED Di
sp
la
y
De
sc
rip
tio
n
Po
ss
ib
le
C
au
se
s
